Road paver with spraying device

ABSTRACT

The disclosure relates to a road paver that comprises a tractor with a material hopper and a machine frame. The machine frame is pivotably connected to the paving screed by pulling arms and a material spreading auger is disposed in a gap between the tractor and the paving screed. A longitudinal conveyor device extends through a tunnel between the material hopper and the gap. The road paver according to the disclosure is characterized by a spraying device that is configured for injecting a liquid into the gap between the tractor and the paving screed or into the tunnel or into the material hopper.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority benefits under 35 U.S.C. §119(a)-(d) to European patent application number EP 16187612.3, filedSep. 7, 2016, which is incorporated by reference in its entirety.

TECHNICAL FIELD

The disclosure relates to a road paver.

BACKGROUND

Road pavers are mostly used in road construction. There, they are usedfor spreading, smoothing and compacting of different types of bulkmaterial. The bulk material can for example be asphalt mixtures. Butmaterials, which are used for the substructure that carries thedifferent asphalt layers of a road, can also be spread, smoothed andcompacted by road pavers.

In some cases, the substructure is moistened from above by means of tankvehicles with sprinkling systems after preparation by a road paver or agrader. Therefore, the substructure has to be accessed by thesevehicles. Compacting by means of rollers can take place afterwards. Asthe substructure materials are often loose bulk materials, i.e., withoutthe addition of binding agents, driving on the substructure has negativeconsequences for the surface quality of the substructure and hence forthe quality and stability of the future road.

SUMMARY

A purpose of embodiments according to the disclosure is to improve thesurface quality of substructure layers in road construction.

A road paver according to the disclosure comprises a tractor with amaterial hopper and a machine frame, wherein the machine frame ispivotably connected to a paving screed by pulling arms. A materialspreading auger is disposed in a gap between the tractor and the pavingscreed. A longitudinal conveyor device extends through a tunnel betweenthe material hopper and the gap. The road paver according to thedisclosure is characterized by a spraying device that is installed forspraying a liquid into the gap between the tractor and the paving screedor into the tunnel or into the material hopper. Therefore, thesubstructure bulk material can be moistened prior to smoothing and,where applicable, compacting so that—possibly with the exception of thefinal compacting roller vehicles—no further vehicles have to drive overthe installed substructure. Additional advantages of spraying into thegap between the tractor and the paving screed consist in the liquidbeing mixed with the paving material, which ensures a more homogeneouswater distribution in the substructure. In addition, swirling of dust isreduced. In connection with the present disclosure, spraying and/orinjection shall be understood as spreading a liquid. In this process,vaporization or fogging can take place. However, this is not requiredfor implementing the disclosure. A spraying and/or injection process inthe sense of the present disclosure can also mean, for example, that theliquid flows out of a tube end. The liquid can for example be water.

It is advantageous for the spraying device to be disposed in the gap.This way, the path that the liquid has to travel from the sprayingdevice to the destination can be reduced and liquid losses, e.g.,through evaporation, can be avoided.

It is possible for the spraying device to be fastened on the machineframe or on the paving screed. However, it is equally conceivable forthe spraying device to be fastened on at least one of the pulling armsor on a fastening device that is disposed for connecting the pavingscreed to the pulling arms.

It is expedient for the spraying device to have one or several outletdevices where the liquid selectively flows out. In particular, if thereare multiple outlet devices, it can be advantageous to let the liquidflow out on only one or multiple ones of the outlet devices as required.In particular, the direction and the quantity of the liquid that flowsout per time unit can be adjustable as will be described in greaterdetail in the following.

It is particularly advantageous if the outlet devices have respectivelyone adjusting element that is configured for variable adjustment of aliquid flow out of the respective outlet device. This way, the liquidflow and/or the liquid flows can be adapted even more accurately to therequirement. The adjusting elements can be operable manually orautomatically. Mechanical or electrical actuation can be provided. Inaddition, the adjusting elements can be remote-controlled and/oroperable directly on the adjusting element. The adjusting element and/orthe adjusting elements can for example be one or multiple ball valves.The outlet devices can have for example one or multiple sprayingnozzles, tongue-type nozzles or vaporization devices. However, also oneor multiple tube ends is/are conceivable.

The spraying device can preferably have one or multiple couplingdevices. For example, two coupling devices can be disposed on oppositesections of the spraying device.

It is possible that an inflow device is disposed on the spraying device.Said inflow device can enable and/or facilitate supply of the sprayingdevice with liquid. For this purpose, the inflow device can be connectedto the spraying device for example through the coupling device and/orone of the coupling devices. The inflow device can comprise for examplea supply line. The inflow device can extend from the spraying device toa different location of the road paver and therefore facilitate theconnection of the spraying device to a liquid supply such as a hydrant,a tank truck or a liquid supply carried along by the road paver or anon-board liquid reservoir.

It is advantageous for the inflow device to be fastened detachably onthe spraying device. Therefore, it can be decided situationally ifand/or where the inflow device is required or useful, and it is possiblethat the liquid supply is connected directly, i.e., without using aninflow device, to the spraying device, for example via the couplingdevice.

It is particularly advantageous if an adjusting unit for variableadjustment of a liquid flow to the spraying device is provided. This canenable an adjustment of the liquid flow to the spraying device up to acomplete switch-off. This can be advantageous in relation to anindividual adjustment at the outlet device. The adjusting unit can forexample be a valve or a flow controller. An adjusting unit can beprovided alternatively or in addition to the adjusting element(s).

Different variants of arranging the adjusting unit are possible. Forexample, it is conceivable for the adjusting unit to be disposed on theinflow device and/or on the spraying device. An arrangement on theinflow device and the spraying device can for example exist if theadjusting unit is provided between the two. The adjusting unit can bedisposed for example on an end section of the inflow device that facesaway from the spraying device or on the end section of the inflow devicethat faces the spraying device.

Advantageously, the adjusting unit can be controlled electronically.This way, activation, deactivation or adjustment of the liquid flow canoccur automatically and depending on different parameters. Examples forsuch parameters are for example the actuation of a driving main switch,the velocity of different conveyor devices of the road paver such as thematerial spreading auger or of so-called scraper belts that may beprovided, or the state of different material quantity sensors such asultrasound or paddle sensors. In addition, or as an alternative to anelectronic control, also a hydraulic or pneumatic control of theadjusting unit is conceivable. These may enable or facilitate theautomation explained above as well.

In a further variant, the adjusting unit can have an adjustable flowcontroller for adjusting the liquid flow.

Regardless of the control of the adjusting unit, it is advantageous inaddition for the adjusting elements to be controllable in an electronicway. Therefore, activation, deactivation or adjustment of the liquidflow can occur automatically and depending on different parameters.Examples for such parameters are the operation of a driving main switch,the velocity of different conveyor devices of the road paver, e.g., thematerial spreading auger or so-called scraper belts that may beprovided, or the state of different material quantity sensors such asultrasound or paddle sensors. In addition, or as an alternative to anelectric control, also a hydraulic or pneumatic control of the adjustingelement(s) is conceivable. These may enable or facilitate the automationexplained above as well.

In a further variant, the adjusting element(s) can have an adjustableflow controller for adjusting the liquid flow.

It is conceivable for the spraying device to be disposed between two ofthe pulling arms. Such an arrangement is in particular advantageous forrigid, non-extended paving screeds. In extending screeds or screeds thatare widened by rigid widening parts, widening units can be mountable onthe spraying device, in particular by one or multiple ones of thepreviously mentioned coupling devices. Said widening units can have oneor multiple further outlet devices that may correspond to the ones ofthe spraying device. It is conceivable for the widening units to be notdisposed between two pulling arms, but only next to one of said pullingarms. It is also possible that the widening units extend laterallybeyond the width of the tractor. It is advantageous for the wideningunits to have a variable width, e.g., by extending devices.

The disclosure relates to a road paver of the previously described type.In the following, an embodiment will be explained in greater detail bymeans of drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a conventional road paver;

FIG. 2 shows a detail view of parts of the road paver according to thedisclosure with a spraying device;

FIG. 3 shows a perspective view of a spraying device according to thedisclosure according to a first embodiment;

FIG. 4 shows a perspective view of a spraying device according to thedisclosure according to a second embodiment;

FIG. 5 shows a schematic display of different components that can beprovided for open-and/or closed-loop control of an amount of liquidspread by the spraying device;

FIG. 6 shows a perspective view of a road paver according to thedisclosure according to a further embodiment; and

FIG. 7 shows a detail view of parts of a road paver according to thedisclosure with a spraying device according to a further embodiment.

DETAILED DESCRIPTION

As required, detailed embodiments are disclosed herein. However, it isto be understood that the disclosed embodiments are merely exemplary andthat various and alternative forms may be employed. The figures are notnecessarily to scale. Some features may be exaggerated or minimized toshow details of particular components. Therefore, specific structuraland functional details disclosed herein are not to be interpreted aslimiting, but merely as a representative basis for teaching one skilledin the art.

FIG. 1 shows a road paver 1 as known from the state of the art. Itcomprises a tractor 2 and a paving screed 3 that is disposed behind saidtractor in the direction of travel. The tractor 2 comprises a machineframe 4 and a material hopper 5 that can be fastened on the machineframe 4. In the area of the material hopper 5, a longitudinal conveyordevice, which can comprise for example one or two scraper belts 22, isprovided. The longitudinal conveyor device extends through a tunnel 26between the material hopper 5 and the gap 7. The paving screed 3 ispivotably installed on the machine frame 4 by pulling arms 6. A gap 7 isprovided between the tractor 2 and the paving screed 3. For the sake ofsimplicity, the previously used reference signs for the respectivecomponents will be used further for the description of a road paveraccording to the disclosure in the following.

FIG. 2 shows a detail view that illustrates only selected components ofa road paver 1 according to the disclosure for a better overview. Out ofthe previously mentioned components, in particular the pulling arms 6are visible. Moreover, the gap 7, which is provided between the tractor2 and the paving screed 3, can be seen. Thanks to the display of onlyselected components, it can now also be seen that a material spreadingauger 8 is disposed in the gap 7. Likewise, a fastening device 9, whichis installed for connecting the paving screed 3 to the pulling arms 6,can be seen. A spraying device 10 is provided in the present embodiment.Said spraying device can for example be disposed in the gap 7. It isconnected to an inflow device 12 through a coupling device 11. Acoupling piece 13 is provided on the end section of the inflow device 12that faces away from the spraying device 10. The coupling piece 13 canbe installed for the connection with a liquid supply. The liquid supplycan for example be a hydrant, a tank truck or a liquid tank that iscarried along on the road paver 1.

FIG. 3 displays the spraying device 10. Now it is apparent that saidspraying device has two coupling devices 11 a, 11 b in the presentembodiment. These are disposed on opposite sections of the sprayingdevice 10 in the present embodiment. However, this can be provideddifferently depending on the installing situation. In the presentembodiment, only one inflow device 12, which is connected to a firstcoupling device 11 a, is provided. A second coupling device 11 b isclosed by a closure 14. Embodiments of the disclosure, in which multipleinflow devices 12 are provided, which can be connected to multiplecoupling devices 11, are possible as well.

An adjusting unit 15 is provided in the present embodiment. Thisadjusting unit 15 can be used to adjust a liquid flow to the sprayingdevice 10 in a variable way. As an example for an arrangement suitablefor this purpose, FIG. 3 shows the arrangement of the adjusting unit 15between the spraying device 10 and the inflow device 12. Alternatively,however, the adjusting unit 15 could also be disposed for example on theend section of the inflow device 12 that faces away from the sprayingdevice 10.

Six outlet devices 16 are provided in the present embodiment. However,this number shall only be regarded as exemplary and can be adapted in asuitable way depending on the purpose of use. For variable adjustment ofa liquid flow that flows out of the respective outlet device 16, oneadjusting element 17 is provided on each outlet device 16. As indicatedin FIG. 3, said adjusting elements can for example be ball valves. Inaddition, the outlet devices 16 of the described embodiment comprisespreading elements 18. These can be configured to spread the liquid flowthat flows out of the respective outlet device 16 and/or to guide saidflow in a specific direction. In the illustrated embodiment, tongue-typenozzles are shown in an exemplary way as spreading elements 18 by whichboth spreading as well as an orientation of the liquid flow can beachieved. However, other spreading elements 18 are also possible, e.g.,spraying nozzles, vaporization devices or a simple tube end.

FIG. 4 shows a spraying device 10 according to a further embodiment. Awidening unit 19 a, 19 b is provided on each of the coupling devices 11a and 11 b. As shown in FIG. 4, these widening units can each have onefurcation 20 a, 20 b. On a first furcation 20 a of a first widening unit19 a, the inflow device 12 can be connected. A second furcation 20 b ofthe second widening unit 19 b is closed by means of the closure 14.However, it is also possible that a second inflow device 12 is providedon the second furcation 20 b. Outlet devices 16 are also provided on thewidening units 19 a, 19b. Said outlet devices have the sameconfiguration possibilities as the outlet devices 16 described withreference to the first embodiment. It is conceivable that they have thesame configurations as the outlet devices 16 provided on the sprayingdevice 10. Alternatively, it is possible that the outlet devices 16 areconfigured differently.

Both the adjusting elements 17 as well as the adjusting unit 15 aredisplayed as simple ball valves in the described embodiments. However,this shall only be understood in an exemplary way. Any devices, whichare suitable to variably adjust an amount of liquid that flows throughthe respective part per time unit, are possible. In particular, valvesthat are configured to vary a flow cross-section are conceivable. It isfor example possible that the adjusting element(s) 17 and/or theadjusting unit(s) 15 each comprise an adjustable flow controller 17 a,15 a. In addition, devices for creating a variable pulsed operation,which creates a variable number of spraying pulses per time unit, ordevices for changing the pressure in the respective tube are possible.

An adjustment of the amount of liquid per time unit can occur forexample mechanically, electromechanically, hydraulically orpneumatically. It is further conceivable that the adjustment can beeffected on the respective adjusting element 17 and/or the adjustingunit 15. In addition, or as an alternative, a remote actuation can beprovided. An electromechanical, hydraulic or pneumatic actuation thatcan be triggered and/or implemented remotely by a control unit 21 (seeFIG. 5) is particularly advantageous. The control device 21 can in thiscontext be an electronic, a hydraulic or pneumatic control device. Itcan comprise a closed control loop or an open control path.

The actuation can occur in an automated way depending on differentparameters of the road paver, e.g., of the actuation of a driving mainswitch 23, a velocity of different conveyor devices of the road paver 1,for example of the material spreading auger 8 or the scraper belts 22,or one or multiple output signal(s) of one or multiple material quantitysensor(s) 24 (see FIG. 5) that can be provided for detecting differentmaterial amounts at different locations in or on the road paver 1.

FIG. 5 is an exemplary schematic representation of a possible embodimentof the actuation of the adjusting element(s) 17 and/or the adjustingunit(s) 15. Inputs 25 are taken into account during actuation of theadjusting element(s) 17 and/or the adjusting unit(s) 15. Inputs 25 shallbe understood as parameters that can be taken into account for anautomated actuation of the adjusting element(s) 17 and/or the adjustingunit(s) 15; the ones mentioned in the previous section are illustratedexemplarily in FIG. 5.

It should be clear that not all of the inputs 25 displayed at the top ofFIG. 5 have to be implemented. It is also conceivable to consider onlyone or multiple of these inputs 25 during actuation of the adjustingelement(s) 17 and/or the adjusting unit(s) 15. Likewise, it should beclear that, as an alternative, only the adjusting element(s) 17 or onlythe adjusting unit(s) 15 can be actuated by the control device 21 and/ordepending on one or multiple of the inputs 25.

FIG. 6 shows a road paver 1 according to a further embodiment of thedisclosure. This road paver has a spraying device 10 that is configuredfor injecting a liquid into the material hopper 5. It is fastened on themachine frame 4. In this embodiment as well, the spraying device 10 hasseveral outlet devices 16. Said outlet devices have the sameconfiguration possibilities as the outlet devices 16 described withregard to the first and second embodiment.

FIG. 7 shows a detail view of a road paver 1 according to a furtherembodiment of the disclosure. Dashed lines indicate that a sprayingdevice 10 is disposed within the tunnel 26. This spraying device isconfigured for injecting liquid into the tunnel 26, in particular on thematerial that is conveyed through the tunnel 26. In this embodiment aswell, the spraying device 10 has several outlet devices 16. These outletdevices have the same configuration possibilities as the outlet devices16 described with regard to the first and the second embodiment.Alternatively, it is conceivable that the spraying device 10 is disposedoutside of the tunnels 26 and configured for injecting liquid into thetunnel.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms according to thedisclosure. In that regard, the words used in the specification arewords of description rather than limitation, and it is understood thatvarious changes may be made without departing from the spirit and scopeof the disclosure. Additionally, the features of various implementingembodiments may be combined to form further embodiments according to thedisclosure.

What is claimed is:
 1. A road paver comprising: a tractor including amaterial hopper and a machine frame; a paving screed pivotably connectedto the machine frame by pulling arms; a material spreading augerdisposed in a gap between the tractor and the paving screed; alongitudinal conveyor device that extends through a tunnel between thematerial hopper and the gap; and a spraying device that is configuredfor injecting a liquid into the gap between the tractor and the pavingscreed or into the tunnel or into the material hopper.
 2. The road paveraccording to claim 1 wherein the spraying device is disposed in the gap.3. The road paver according claim 1 wherein the spraying device isfastened on the machine frame or on the paving screed.
 4. The road paveraccording to claim 1 wherein the spraying device is fastened on at leastone of the pulling arms or on a fastening device that is configured toconnect the paving screed to the pulling arms.
 5. The road paveraccording to claim 1 wherein the spraying device has one or more outletdevices through which the liquid may selectively flow.
 6. The road paveraccording to claim 5 wherein each of the one or more outlet devices hasan adjusting element that is configured for variable adjustment of aliquid flow out of the respective outlet device.
 7. The road paveraccording to claim 5 wherein the one or more outlet devices comprisesmultiple outlet devices, and wherein an adjusting element is provided,which is configured for variable adjustment of a liquid flow to a groupof the outlet devices, wherein the group of outlet devices comprises atleast two outlet devices.
 8. The road paver according to claim 1 whereinan inflow device is provided on the spraying device.
 9. The road paveraccording to claim 8 wherein the inflow device is fastened detachably onthe spraying device.
 10. The road paver according to claim 1 furthercomprising an adjusting unit for variable adjustment of a liquid flow tothe spraying device.
 11. The road paver according to claim 10 furthercomprising an inflow device provided on the spraying device, and whereinthe adjusting unit is disposed on the inflow device and/or on thespraying device.
 12. The road paver according to claim 10 furthercomprising an inflow device provided on the spraying device, wherein theadjusting unit is disposed between the spraying device and the inflowdevice.
 13. The road paver according to claim 10 wherein the adjustingunit is electronically controllable.
 14. The road paver according toclaim 10 wherein the adjusting unit has an adjustable flow controllerfor adjusting the liquid flow.
 15. The road paver according to claim 1wherein the spraying device is arranged between two of the pulling arms.16. A road paver comprising: a tractor including a material hopper and amachine frame; a paving screed pivotally connected to the machine frame;a material spreading auger disposed in a gap between the tractor and thepaving screed; a longitudinal conveyor device that extends through atunnel between the material hopper and the gap; and a spraying deviceconfigured to inject a liquid into the gap between the tractor and thepaving screed or into the tunnel or into the material hopper.